The invention relates to a television signal processing device for autonomously determining television program information, having receiving means for receiving a television signal in a receiving channel receivable by the receiving means and for receiving an information signal which comprises data blocks containing data block information and which is receivable recurrently in blanking intervals of the television signal, and having an information detection stage for detecting data block information identified by a given data block address in each receiving cycle of the received information signal, and having television program information determining means for determining television program information contained in data block information detected by means of the information detection stage and for presetting at least one further data block address for the information detection stage in order to determine further television program information contained in the information signal, and having a switching stage for autonomously switching over the receiving means for the reception of at least one further television signal comprising an information signal in blanking intervals via at least one further receiving channel so as to enable further television program information to be determined autonomously.
Such a television signal processing device of the type defined in the opening paragraph, included in a television set, is known from the document is known from the document EP 0 337 336 A2. The known television set has receiving means with which it is possible to receive a television signal from a television station as for example ARD, ZDF or CNN in a receiving channel. A received television signal can be displayed as a television program on a viewing screen of the television set.
The receiving means are further adapted to receive an information signal transmitted in blanking intervals of a television signal. The information signal conveys digital data including VPS information (Video Program System; European Telecom Standard ETS 300 231) and teletext information. Each television program received as a television signal is identified by given VPS information. VPS information also includes television signal identification information which identifies a television signal and by means of which the television station which makes a television signal available and which transmits this signal can be identified. Teletext information of a television signal may include television program information about television programs of one or more receiving channels which can be received, for example, within the next week. Television program information can be formed by digital data representative of television signal identification information, the date, the starting and ending time, the title as well as the VPS information of a television program.
Teletext information can be received as data block information in data blocks formed by teletext pages, in successive receiving cycles of equal contents which recur approximately every 30 to 60 seconds. The known television set has an information detection stage formed by a teletext microprocessor which can be preset to a teletext page formed by a data block address. and which is adapted to detect the teletext page identified by the teletext page number and contained in the teletext information.
The known television set further comprises television program information determining means for determining and storing television program information contained in teletext information contained in the television signals which can be received by the receiving means. For this purpose, the television program information determining means use a television program information determining algorithm with which television program information is determined by presetting teletext page numbers for the teletext microprocessor and by evaluating the teletext information detected by the teletext microprocessor for a received television signal and said television program information is stored in a television program memory. In accordance with the television program information determining algorithm, after television program information has been derived from the teletext information of a television signal, the receiving means can be switched over independently by a switching stage in order to receive a further receivable television signal which transmits teletext information in the blanking intervals of the television signal in order to derive television program information from the teletext information of this television signal and store this in the television program memory. The receiving means can be switched over so often by the switching stage in order to receive a further television signal that television program information from all the information signals of receivable television stations is received and is stored in the television program memory. In the known television set the television program information determining algorithm is carried out fully autonomously and automatically once a day, for example in the morning because time television sets are generally not used at this time.
During the execution of the television program information determining algorithm the known television set is adapted to detect teletext page numbers which refer to teletext pages from which television program information can be derived. For this purpose, the television program information determining means are adapted to compare VPS information currently received by the receiving means with teletext information received during a receiving cycle. When the received VPS information is found in the received teletext information a teletext page number can be detected which identifies the teletext page containing this VPS information. The detected teletext page number can be applied to the information detection stage by the television program information determining means in order to detect teletext information identified by the teletext page number during the next receiving cycle. Further television program information can be derived from teletext pages bearing increasing teletext page numbers.
By the actuation of a key of the remote control device of the known television set the television set can display a list of receiving suggestions which is derived from the television program information stored in the television program memory and which contains the titles and starting times of television programs and television signal identification information of the television stations from which these television programs can be received currently or shortly.
However, with the known television set it has been found that the detection of teletext page numbers which identify teletext page numbers from which television program information can be derived cannot be effected reliably because temporarily VPS information, which serves to identify a currently receivable television program, is not presented and transmitted correctly by the television stations or because television program information contained in a teletext page temporarily contains incorrect VPS information about a television program. Moreover, VPS information may have been presented and transmitted correctly by a television station or may appear correctly in the television program information but may not be received correctly as a result of a comparatively poor reception quality of the received television signal. In both cases the television program information determining means cannot detect agreement between VPS information received by the receiving means and VPS information contained in the teletext information received during a receiving cycle. As a consequence, no television program information can be derived from a television signal from such a television station in such cases, as a result of which a list of receiving suggestions generated by means of the detected television program information is incomplete.
Furthermore, the television program information determining algorithm of the known television set requires relatively much time to determine television program information because it is first necessary to derive for each receiving channel a first teletext page number of a teletext page containing television program information from the information signal before subsequently further television program information of further teletext pages is determined.
Moreover, the known television set only enables the detection of television program information from television stations which transmit VPS information, as a result of which the list of receiving suggestions can display only television programs from a comparatively smaller number of television stations.
It is an object of the invention to eliminate the afore-mentioned problems and to provide an improved television signal processing device of the type defined in the opening paragraph. In a recording arrangement of the type defined in the opening paragraph this object is achieved in that a data block address memory has been provided, in which at least one item of television signal identification information, which identifies a received television signal, or receiving channel identification information can be stored in correlation with at least one data block address which identifies a data block of an information signal contained in a television signal received in a receiving channel, and in that each time that television program information is determined successfully in detected data block information, the television program information determining means are adapted to autonomously store the last preset data block address in the data block address memory in correlation with television signal identification information, which identifies the received television signal, or receiving channel identification information, and in that after switching over of the receiving means by the switching stage a data block address stored in the data block address memory in correlation with television signal identification information, which identifies the received television signal, or receiving channel identification information, can be applied autonomously to the information detection stage by the television program information determining means in order to detect data block information identified by the data block address. Thus, it is achieved that during an autonomous determination of television program information by means of the television signal processing device the television program information determining means can read a data block address from the data block address memory from whose associated data block formed by a teletext page already television program information could be derived successfully during a preceding determination of television program information. A successful determination of television program information can be detected by checking whether the teletext information contained in a detected teletext page complies with a standard for television program information, such as for example the VPT standard (Video recorder Programming by Teletext). Thus, it is possible to realize a television program information determining algorithm for which it is not necessary to determine each time anew teletext page numbers which identify teletext pages from which television program information is derivable. Consequently, such a television program information determining algorithm allows television program information to be determined particularly reliably and rapidly.
On the one hand, teletext page numbers of teletext pages from which television program information has been derived with success can be stored in correlation with television signal identification information, which has the advantage that a television signal from a television station which can be received via a plurality of receiving channels is always stored in correlation with the same last determined teletext page number. On the other hand, such teletext page numbers can also be stored in correlation with receiving channel identification information which identifies the receiving channel via which the television signal is received, which has the advantage that this is possible independently of the fact whether television signal identification information can be derived from the received television signal.
For the first time successfully determining teletext page numbers which identify teletext pages containing television program information can be effected, for example, as in the known television set by comparing received VPS information with VPS information received in teletext information. However, such teletext page numbers may also be stored in the television signal processing device during the manufacture of the television signal processing device, or they can be determined in a particularly advantageous manner in accordance with the measures defined in Claim 3.
It is to be noted that a further television signal processing device is known from the document DE 35 27 939 C2, which device has a memory in which television signal identification information identifying a receivable television signal can be stored in correlation with at least one data block address formed by a teletext page number. In a television program information determining algorithm television program information is derived from special teletext pages identified by stored teletext page numbers, which special teletext pages have been prepared for this by the television station and contain given television program information. In this known television signal processing device the teletext page numbers should be entered by a user via a control device, which is a great disadvantage in comparison with the television signal processing device in accordance with the invention. Furthermore, when a television station changes teletext page numbers of such special teletext pages, a user should again enter teletext page numbers by means of a control device in order to ensure that the television program information contained in these special teletext pages remains subsequently available. Moreover, the special teletext pages contain only television program information of the currently receivable television program and a television program which is receivable subsequently to the received television signal, as a result of which a list of receiving suggestions derived from this television program information is only of little value for the user.
In a television signal processing device as defined in Claim 1 it has proved to be advantageous to take the measures defined in Claim 2. Thus, it is achieved that once television program information has been detected for a multitude of television programs from different television stations can be selected in accordance with search criteria such as keywords, VPS information or starting times in order to draw up a selection of television programs which are of interest to the user and to display this selection in a list of receiving suggestions. Furthermore, by deriving the television program information from the data block information and storing only the television program information in the television program memory the storage capacity of the television program memory is used particularly efficiently.
In a television signal processing device as defined in Claim 1 it has proved to be advantageous to take the measures defined in Claim 3. Preferential data block addresses which are formed by teletext page numbers and which identify teletext pages with teletext information from which further teletext page numbers can be derived which identify further teletext information from which television program information can de derived, are known for example as so-called xe2x80x9cBasic TOP Tablexe2x80x9d, xe2x80x9cMulti Page Tablexe2x80x9d or xe2x80x9cMagazine Inventory Pagexe2x80x9d (ARD/ZDF/ZVEI Guideline: xe2x80x9cTOPxe2x80x9d System for Teletext). Determining television program information can be effected particularly rapidly and reliably when in accordance with the measures defined in Claim 3 television program information is derived directly from the teletext pages defined in the preferential data block information by the television station.
In a television signal processing device as defined in Claim 3 it has proved to be advantageous to take the measures defined in Claim 4. As a result of this, it is achieved that television program information which can be received in data sub-blocks formed by teletext sub-pages in a plurality of receiving cycles in succession and, consequently, not in each receiving cycle of the information signal can be determined particularly reliably and rapidly. This is because it is not necessary to observexe2x80x94as stated for example in EP 0 447 968 B1xe2x80x94waiting cycles to determine whether a teletext page has teletext sub-pages. Moreover, this prevents a teletext sub-page contained in the information signal from being overlooked.
In a television signal processing device as defined in Claim 3 it has proved to be advantageous to take the measures defined in Claim 5. As a result of this, it is achieved that, for determining data block information the information detection stage can only be preset to data block addresses which identify data blocks which are actually transmitted in the received information signal. This precludes waiting times which would occur if the information detection stage would be preset to a data block address that is not transmitted in the information signal.
In a television signal processing device as defined in Claim 1 it has proved to be advantageous to take the measures defined in Claim 6. Thus, it is achieved that, starting from a first data block address which identifies a data block from whose data block information most recently television program information could be derived with success, television program information can be determined systematically from adjacent data blocks. This is advantageous particularly because in most cases television program information is contained in data block information of adjacent data blocks, such as for example in the teletext pages 301 to 304 and the television program information can thus be determined particularly rapidly.
In a television signal processing device as defined in Claim 1 it has proved to be advantageous to take the measures defined in Claim 7. Thus, it is achieved that additional information for an information signal which has already been determined once by the television program information determining means and which can be used advantageously during a subsequent determination of television program information, need not be determined again. Additional information can be, for example, information that VPS information, VPT information or time information has already been detected one time in teletext information, or information whether a teletext page has teletext sub-pages.
In a television signal processing device as defined in Claim 3 it has proved to be advantageous to take the measures defined in Claim 8. Thus, it is achieved that television program information can be determined in parallel from teletext information of at least two teletext pages, which enables television program information to be determined even more rapidly.
It has proved to be advantageous to include a television signal processing device as defined in Claim 1 in a recording and/or reproducing arrangement. As a result of this, a recording and/or reproducing arrangement such as for example a video recorder is obtained by means of which television program information can be determined autonomously as well as reliably and rapidly from a plurality of teletext information items transmitted in blanking intervals of television signals.
The afore-mentioned as well as further aspects of the invention will be apparent from the embodiment described hereinafter by way of example and will be elucidated with reference to this embodiment.